GRB2 Promotes Thymocyte Positive Selection by Facilitating THEMIS-Mediated Inactivation of SHP1

Researchers showed that similar to Themis−/− thymocytes, the primary molecular defect in GRB2-deficient thymocytes was increased catalytically active SHP1 and the developmental block in GRB2-deficient thymocytes was alleviated by deletion or inhibition of SHP1 and exacerbated by SHP1 overexpression.